Ancient Greece is the term used to describe the Greek-speaking world in ancient times. It refers not only to the geographical peninsula of modern Greece, but also to areas of Hellenic culture that were settled in ancient times by Greeks: Cyprus, the Aegean coast of Turkey (then known as Ionia), Sicily and southern Italy (known as Magna Graecia), and the scattered Greek settlements on the coasts of what are now Albania, Bulgaria, Egypt, Libya, southern France, southern Spain, Catalonia, Georgia, Romania, and Ukraine.
There are no fixed or universally agreed upon dates for the beginning or the end of the Ancient Greek period. In common usage it refers to all Greek history before the Roman Empire, but historians use the term more precisely. Some writers include the periods of the Greek-speaking Mycenaean civilization that collapsed about 1100 BC, though most would argue that the influential Minoan was so different from later Greek cultures that it should be classed separately.
In the modern Greek school-books, "ancient times" is a period of about 1000 years (from the catastrophe of Mycenae until the conquest of the country by the Romans) that is divided in four periods, based on styles of art as much as culture and politics. The historical line starts with Greek Dark Ages (1100–800 BC). In this period artists use geometrical schemes such as squares, circles, lines to decorate amphoras and other pottery. The archaic period (800–500 BC) represents those years when the artists made larger free-standing sculptures in stiff, hieratic poses with the dreamlike "archaic smile". In the classical years (500–323 BC) artists perfected the style that since has been taken as exemplary: "classical", such as the (Parthenon). In the Hellenistic years that followed the conquests of Alexander (323–146 BC), also known as Alexandrian, aspects of Hellenic civilization expanded to Egypt and Bactria.
Traditionally, the Ancient Greek period was taken to begin with the date of the first Olympic Games in 776 BC, but many historians now extend the term back to about 1000 BC. The traditional date for the end of the Ancient Greek period is the death of Alexander the Great in 323 BC (The following period is classed Hellenistic) or the integration of Greece into the Roman Republic in 146 BC.
The Roman Empire is the term conventionally used to describe the Ancient Roman polity in the centuries following its reorganization under the leadership of Octavian (better known as Augustus). After Constantinople had been made capital and the Western parts were lost, the Eastern part became known as the Byzantine Empire.
Roman Empire is also used as translation of the expression Imperium Romanum, probably the best known Latin expression where the word "imperium" is used in the meaning of a territory, the "Roman Empire", as that part of the world where Rome ruled. The expansion of this Roman territory beyond the borders of the initial city-state of Rome had started long before the state organisation turned into an Empire. One of the first historians to describe this expansion of the Roman territory was the Greek Polybius, writing in the Epoch of the Roman Republic. In its territorial peak after the conquest of Dacia by Trajan, the Roman Empire controlled approximately 5,900,000 sq.km., or 2,300,000 sq.mi. of land surface, thereby being the largest of all empires during the classical antiquity period of European history.
In the centuries before the autocracy of Augustus, Rome had already accumulated most of its territory beyond the Italian Peninsula, including former Mediterranean competitors Syracuse and Carthage. In the late Republic, Augustus (then still "Octavian") definitively added Egypt to the Imperium Romanum. The remainder of this article treats the Roman Empire as an Imperial state (see Roman Kingdom and Roman Republic for development of the territory in earlier times).
Augustus' reforms turning the Roman state into an empire survived mostly unchanged until the Diocletian reform at end of the 3rd century, which turned the empire into a tetrarchy. While the political form given by Diocletian was short-lived, it led to the division of the Empire into two halves. This allowed Roman rule to continue for two more centuries over the whole empire, although divided into the Eastern and the Western Roman Empire.
The end of the Western Empire is traditionally set as 4th September 476 a.d., when the Germanic chieftain Odoacer forced the abdication of the last Western Emperor Romulus Augustus and sent the Imperial insignia to Constantinople; henceforth Odoacer ruled nominally as dux on behalf of Constantinople. After another millennium in 1453 a.d., the Eastern Empire, better known as the Byzantine Empire, fell to the Ottoman Turks.
From Augustus to the Fall of the Western Empire, Rome dominated the region of Western Eurasia comprising over half its population. The legacy of the Roman empires on the culture, law, language, religion, government, military, and architecture of Western civilization remains to this day.
The Greeks adopted the Roman name in the Middle Ages and were known as Romans, a trend that survives until today in Greece, a result of their cultural position (see Names of the Greeks). Roman titles of power were adopted by most of the successor states and later entities with imperial pretensions, including the Frankish kingdom, the Holy Roman Empire, the Bulgarian Empires, the Russian/Kiev dynasties, and the German Empire. See also Roman culture.
Byzantine Empire is the term conventionally used since the 19th century to describe the Greek-speaking Roman Empire during the Middle Ages, centered at its capital in Constantinople. In certain specific contexts, usually referring to the time before the fall of the Western Roman Empire, it is also often referred to as the Eastern Roman Empire. There is no consensus on the starting date of the Byzantine period. Some place it during the reign of Diocletian (284–305) due to the administrative reforms he introduced, dividing the empire into a pars Orientis and a pars Occidentis. Others place it during the reign of Theodosius I (379–395) and Christendom's victory over paganism, or, following his death in 395, with the division of the empire into western and eastern halves. Others place it yet further in 476, when the last western emperor, Romulus Augustus, was forced to abdicate, thus leaving sole imperial authority to the emperor in the Greek East. In any case, the changeover was gradual and by 330, when Constantine I inaugurated his new capital, the process of further Hellenization and increasing Christianization was already underway.